Seeing that the server of Boinc Beta was capable to download WU's again, I reattached to the project using the URL and my account ID of the project I assigned for at Boinc Beta. The project I had at Boinc Beta was up to the latest WU's "Astropulse Beta".

The client gets into a state when adding a project where it thinks it needs more work even though it doesn't. So it does a RPC to the next available project. The new project is still waiting on a master fetch so it is not available for a normal RPC.